The impact of different diuretics on regression of myocardial reperfusion injury in spontaneously hypertensive rats

Abstract

The study's objective was to ascertain the results of sub-chronic therapy of various diuretics on the ischemia/reperfusion dysfunction of the heart in hypertensive rats by a global ischemia in an isolated rat heart model. The research included 40 spontaneously hypertensive male rats (Wistar Kyoto strain, body mass 250 ± 30 g, 8 weeks old) grouped into four groups. The animals were treated for 4 weeks with 10 mg/kg of hydrochlorothiazide, indapamide, or spironolactone per os. After a period of sub-chronic treatment, we analyzed hemodynamic measurements, echocardiography, and myocardial function according to the Langendorff retrograde perfusion method. The hearts were subjected to 20 min of global ischemia and then reperfused for 30 min (I20:R30). Cardiovascular parameters that depict the left ventricle functions were continuously monitored, while flowmetry was used to determine coronary flow values. Markers of oxidative stress were estimated from coronary venous effluent using spectrophotometry. All three examined diuretics (hydrochlorothiazide, spironolactone, indapamide) lowered the production of the majority of the detected prooxidants, reducing myocardial oxidative damage. The cardiological examination of heart function in vivo demonstrated that treatment with indapamide and spironolactone mitigates left ventricular hypertrophy but without significant lowering of blood pressure or increment in ejection fraction. Additionally, monitoring of cardiac function ex vivo indicated the cardiodepressant effect of spironolactone in spontaneously hypertensive rats.